All 4 lanes of I-5 are closed (all north & south lanes) in a major collapse of the bridge over the Skagit River near Mount Vernon, WA. Several vehicles were on the bridge at the time of the bridge's structural failure. So far, no deaths reported, but it is early and reports are incomplete. Several people were rescued from their vehicle rooftops.
Bridge was built in 1955.
This is probably the biggest North-South transportation corridor on the west coast.
UPDATE: Apparently a semi truck with an oversized load over 12 ft. wide and 14 ft. tall made contact with structural elements of the bridge resulting in sheared girders which weakened the span enough to cause structural collapse. Pilot car wasn't far enough ahead (doing 60mph) to stop the truck before contact.